Re: [Qemu-devel] [Qemu-block] [PATCH] block: fix write with zero flag set and iovector provided

[Anton Nefedov]

On 1/2/2018 5:29 PM, Alberto Garcia wrote:
> On Thu 01 Feb 2018 03:16:31 PM CET, Anton Nefedov wrote:
> > The normal bdrv_co_pwritev() use is either
> >    - BDRV_REQ_ZERO_WRITE reset and iovector provided
> >    - BDRV_REQ_ZERO_WRITE set and iovector == NULL
> >
> > while
> >    - the flag reset and iovector == NULL is an assertion failure
> >      in bdrv_co_do_zero_pwritev()
>
> Where is that assertion?
>
> Berto

beginning of bdrv_co_do_zero_pwritev():

    assert(flags & BDRV_REQ_ZERO_WRITE);

and bdrv_co_do_zero_pwritev() was only called with qiov==NULL.

Now this case will instead segfault at some point.
Don't know if it needs a separate assertion.

/Anton